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Vulnerabilities

Vulnerability · CVE-2026-4740

A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM).

Published Apr 7, 2026 · catalog updated Sep 8, 2026 · Red Hat advanced cluster management for kubernetes

Check if you run it

No confirmed exploitation is on record for CVE-2026-4740. EPSS is 0.16%. Act only if a listed version of Red Hat advanced cluster management for kubernetes is installed.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High8.2
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.16%
Remediation
Advisory link
Affected products
cpe redhat/advanced cluster management for kubernetes

A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other managed clusters, including the hub cluster.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe redhat/advanced cluster management for kubernetesversion unspecified

How to fix CVE-2026-4740

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-4740. EPSS is 0.16%. Act only if a listed version of Red Hat advanced cluster management for kubernetes is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-295: Improper Certificate Validation. EPSS 0.16%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Kubernetes security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 7, 2026 · NIST NVD

    Detected

    A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other manag

  2. Sep 8, 2026 · NIST NVD

    Updated

    A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other manag

Sources

  • CSAF AdvisoriesVendor advisoryRHSA-2026:9848:CVE-2026-4740

    A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OC

    security.access.redhat.com
  • CVE.orgVulnerability recordCVE-2026-4740

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-4740

    30-day exploitation probability 0.2%

    first.org
  • NIST NVDVulnerability recordCVE-2026-4740

    A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OC

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.